Implement hover and go to definition providers for citations

[Dominic-DallOsto]

Addresses #28

Hover provider:

Go to definition provider (Ctrl + hover):

This is mostly a simplified version from LaTeX workshop's hover provider and go to definition provider.

• For the hover provider, I had to replace newlines in the text with two spaces then a newline, otherwise everything rendered on one line. LaTeX Workshop does this when parsing the documentation initially here - I'm not sure if it's worth doing the same
• I'm not convinced my regexp to select the citation key is robust - do you have any advice? And since it's reused twice, would it be worth spinning out to a separate function/file?

[mihaiconstantin]

I can try to help with the regex, but first I need to make sure I understand how the matching should happen. Based on lines 14 and 15 I deduce that you need two positions:

• startResult: match words that follow after @ until a space or line end
• endResult: what should it match?

One final question, can we use a positive lookbehind assertion? Based on this page, it seems to be possible from ECMAScript 2018.

Would the following work (i.e., see demo here)?

• startResult: (?<=@)\w+, or to allow for - in the citation key (?<=@)[\w|-]+

[mihaiconstantin]

But personally, I find your option already very good (i.e., demo here).

[Dominic-DallOsto]

Sorry, I based that method on how it was done in LaTeX Workshop so it was probably a bit confusing. I just found a nice inbuilt VSCode function to make getting a word at the current cursor position much easier. It should be clearer now.

Should dashes be allowed in the citation keys in general?

[mihaiconstantin]

Sorry, I based that method on how it was done in LaTeX Workshop so it was probably a bit confusing. I just found a nice inbuilt VSCode function to make getting a word at the current cursor position much easier. It should be clearer now.

No worries! I am happy to hear VSCode has a built-in function for that!

Should dashes be allowed in the citation keys in general?

According to this answer on TeX there a range of characters that can be used as delimiters for BibTeX keys. However, I propose to keep it simple and ignore this for now. I can imagine that these are not very common use cases.

[notZaki]

Wow! Thanks for the excellent contribution @Dominic-DallOsto and for suggesting this in the first place @mihaiconstantin !
I'll merge this and publish a new release.